Brom-valeric-acid menthol ester.



UNITED STATES PATENT OFFICE.

EDUARD SIRUNGERTS, O1 FRANKFORDON-TllE-MAIN, GERMANY, ASSIG-NOR. TO FIRM OF VEREINIWPE CHIN IN FA BRIKEN ZIMMER (St (30., G-ESELLSCILA l..l M Il BESGHRANKTER HAFT U 'NG, OF FRANKFORT-ON-TllE-MAIN, GERMANY.

BROM-VALERIC-ACID MENTHOL ESTER.

Application filed November 25, 1907.

To all whom it may concern:

Be it known that I, EDUARD Srnonennrs, a subject of the German Emperor, and resident of Frankfort-on-the-Main, Germany, have invented certain new and useful Im provements in Brom-Valeric Compounds, of which the following is a specification.

This invention relates to a process of making alpha brom valeric acid-menthol-ester and to the product produced by said process. The menthol-ester of brom-valeric-acid was not known heretofore. Its advantage consists in the fact, that it is free of the unpleasant odor and taste of the acid, while the sedative qualities of the valeric acid are increased by the bromin. The process of manufacturing the same consists in causing the acid itself, or the bromid of the same or the phenol-ester of the same to act on menthol.

Alpha-brom-valericacid-mentholester is a colorless oil, which is heavier than water, and which can easily be dissolved in alcohol, ether, chloroform and benzin, while it is insoluble in water. 'At a pressure of 20 millimeters and at a temperature of 162 to 167 centigrade it boils while being but slightly decomposed. By alcoholic potash the ester is easily saponified hydrobromic acid being simultaneously split off. The analysis of several compounds made showed, on an aver age, 29.09% of bromin, the formula o H 0 so one oil 1o 19 \CH3 requiring 25.08% of bromin.

Examples: I

not of the reaction is washed with diluted ammonia, while cooling, whereupon it is distilled with superheated steam. After a slight fore-shot of menthene-like odor, pure ester is Patented May 26, 1908.

Serial No. 403,791. (Specimens) distilled over. The compound thus obtained is represented by the following equation:

2. 1 kilogram of menthol is dissolved in 2 kilograms of pyridin whereupon 1.600 kilograms of brom-valeric-bromid are added little by little to the said solution while cooling. After the solution has stood for 12 hours, the product of the reaction is washed at first with a diluted solution of caustic soda, and afterwards with diluted hydrochloric acid, whereupon it is distilled with superheated steam.

3. 2 kilograms of brom-valeric acid and 1,600 kilograms of menthol are heated for 8 hours to 150 centigrade. the reaction is washed with diluted alkali, and after drying it is fractionated in 'vacuo. At a pressure of 20 millimeters and at a tem perature of 162 to 167 the brom-Valerieacid-menthol-ester is distilled over. The formation of the ester can be made more speedy by adding grams of concentrated sulfuric acid or 400 grams of oXychlorid of phosphorus or by passing dry hydrochloric or hydrobromic acid gas into the solution. In these cases, it is sufficient to heat the mixture for several hours in the water bath.

4. 2 kilograms of brom-valeric-acid-phenolester are heated with a little more than the corresponding molecular amount, viz. 1300 grams of menthol for several hours in the oil bath to 180 to 190 centigrade, while adding a little caustic potash. The product of the reaction is treated as in Example 1.

Claims:

1. The herein described process of making alpha brom valeric acid menthol ester, which consists in causing the alpl1a-bromvaleric-acid to act on menthol while subject ed to heat, treating the reaction product with alkali, and distilling it by the action of superheated steam.

The product of 2. As gm article ')f' 1nan1:|i."aetere the herein (lesei'ibed precinct ealleil zil'pl1e-brew-Valerieac]cl-menth(ii-ester answering to the fer-mule which compound is a colorless eil heavier than Water and easily soluble in alcohol, ether, chloroform and benzin, While insoluble 10 in water, and whieh at it pressure of 20 niillimeters and at :1, temperature of 162 to 167 eentig'ii'mle boils while being slightly dee0n1- posed.

In testin'ioi'ly whereof I have signed. my nei'ne to this speeiiieation in the presence of two subscribing witnesses. H

EDUARD SPRONGERTS.

Witnesses JEAN GRUND, CARL GRUND. 

